Vita Malacologica 13: 53-56 20 December 2015 Recognizing cephalopod boreholes in shells and the northward spread of Octopus vulgaris Cuvier, 1797 (Cephalopoda, Octopodoidea) Auke-Florian HIEMSTRA Middelstegracht 20B, 2312 TW Leiden, The Netherlands email:
[email protected] Key words: Cephalopods, Octopus , predation, hole-boring, The Netherlands ABSTRACT & Arnold, 1969; Wodinsky, 1969; Hartwick et al., 1978; Boyle & Knobloch, 1981; Cortez et al., 1998; Steer & Octopuses prey on molluscs by boring through their shell. Semmens, 2003; Anderson et al., 2008; for taxonomical Among the regular naticid borings, traces of cephalopod pre - updates see Norman & Hochberg, 2005). However, the habit dation should be found soon on Dutch beaches. Bottom trawl - of drilling may prove to be more widespread within octopods ing has declined, and by the effects of global warming since only few species have actually been investigated Octopus will find its way back to the North Sea where it lived (Bromley, 1993). Drilled holes were found in polypla - before. I describe the distinguishing characters for Octopus cophoran, gastropod and bivalve mollusc shells, Nautilus and bore holes, give an introduction into this type of behaviour, crustacean carapaces (Tucker & Mapes, 1978; Saunders et al., present a short history of Dutch octopuses and a prediction of 1991; Nixon & Boyle, 1982; Guerra & Nixon, 1987; Nixon et their future. al., 1988; Mather & Nixon, 1990; Nixon, 1987). Arnold & Arnold (1969) and Wodinsky (1969) both describe the act of drilling in detail. This behaviour consists INTRODUCTION of the following steps (Wodinsky, 1969): recognizing and selecting the prey, drilling a hole in the shell, ejecting a secre - Aristotle was the first to observe octopuses feed on mol - tory substance into the drilled hole, and removing the mollusc luscs (see D’Arcy Thompson, 1910), but it was Fujita who from its shell and eating it.